The Siemens 3RH2140-1AB00-1AA0 is a Size S00 contactor relay with 4 normally-open contacts, a 24 V AC coil rated for 50/60 Hz, and screw terminals. It mounts upright on a DIN rail inside a control panel, handling signal-level switching for PLC outputs, auxiliary contact chains, or pilot-duty loads.
The 4 NO contact configuration means all four poles close when the coil is energized — no normally-closed break contacts on this variant. The 24 V AC coil draws from a control transformer or dedicated AC supply; verify the control circuit can source the inrush without dropping below the pick-up threshold. Size S00 is the smallest SIRIUS frame, saving DIN-rail space in dense panels.